Employees who work outside – such as in construction, commercial fishing, oil & gas extraction, trucking & warehousing, protective services, interurban transportation, maritime industry & agriculture – are especially vulnerable to cold weather injuries. Individuals with predisposed health conditions (e.g. cardiovascular disease, diabetes, hypothyroidism, asthma or hypertension), older persons, or those taking certain medications are also at an increased risk. Vehicle breakdown – or contact with water , gasoline or alcohol – are noted contributing factors to increased cold-related injuries.
Cold related hazards can cause permanent tissue damage or even death. Four factors contribute to cold stress: cold temperatures, high or cold wind, dampness & cold water. A cold environment forces the body to work harder to maintain its core temperature of 98.6 degrees Farenheit. When in a cold environment, most of the body’s energy is used to keep it’s internal temperature warm. Over time, the body will begin to shift blood flow from the extremities (hands, feet, arms & legs) and outer skin to the core (chest & abdomen). This allows exposed skin & the extremities to cool rapidly & increase the risk of frostbite. When the body can longer maintain core temperature by constricting blood vessels, it shivers to increase heat production. Maximum severe shivering develops when the body temperature has fallen to 95 degrees Farenheit. Hypothermia becomes an issue at this point…
Hypothermia occurs when body heat is lost from being in a cold environment faster than it can be replaced. Hypothermia occurs most often in the spring & fall, rather than is commonly believed to occur in the winter. Symptoms begin with shivering. Early warning signs include physical discomfort (“feeling cold”), minor injuries (such as pulled muscles), loss of feeling & dexterity in fingers, hands & toes, and “frost nip” (which occurs when the outermost layers of skin turn white). As the body temperature continues to fall, the signs of the “unusual -umbles” occurs (e.g. stumbles, mumbles, fumbles & grumbles); these are warning signs that the individual is not coping well with the temperature. If someone in a cold environment can voluntarily stop shivering, or solve a mathematical question, then hypothermia is most likely mild.
These symptoms are followed shortly by slurred speech, loss of alertness, lack of coordination, fatigue, lethargy, apathy & memory loss – and shivering ceases. Once the body temperature falls to about 85 degrees Farenheit, the hypothermia victim may become unconscious; if a pulse can’t be felt at the wrist of a hypothermia victim, this is a sign that the core temperature is less than 90 degrees Farenheit & indicates severe hypothermia. If the victim of severe hypothermia is found in the fetal position, try to open their arms – if they curl back, then the person is still alive (dead muscles will not contract). At 78 degrees Farenheit core body temperature, the hypothermia victim could die.
Anyone working in a cold environment may be at risk for hypothermia. Some workers claim that constant exposure to cold makes them able to withstand these temperatures better. The reality is that workers learn to survive, rather than physically adapt to cold weather work. Getting used to cold weather work – or habituation to cold – may dull the awareness of being cold & carries with it an increased of hypothermia or cold injury. Long hair & beards provide little insulation; they can, in fact, serve as a basis for ice build up & can mask the appearance of frostbite. However, older people are at slightly more risk than younger adults, since older people are not able to generate heat or regulate body temperature as quickly. Certain medications may also prevent prevent the body from generating heat normally; these medications include anti-depressants, amphetamines, sedatives, tranquilizers, hypnotics, thyroid drugs, morphine, psychotropic drugs, diabetes medications & insulin, and some heart medications.
In cases of Mild Hypothermia, move the victim to a warm area, keep them active, remove wet clothes, replace with dry clothes or blankets while covering the head, and have the victim drink warm (NOT Hot) sugary drinks (such as hot chocolate or soups). In Moderate Hypothermia, call 911 for an ambulance, cover the victims extremities completely, and place warm objects (such as hot packs or hot water bottles) on the victim’s head, neck, chest & groin. In the case of an unconscious victim of Severe Hypothermia, do not attempt to re-warm (this treatment will be provided under controlled conditions in a hospital) – call 911 & handle the victim carefully (sudden movement or rough handling can upset the victim’s heart rhythm & send them into cardiac arrest).
Frostbite occurs when layers of skin tissue freeze & ice crystals form in the tissues, damaging them. Small blood vessels can be damaged when they become blocked with tissue debris. This causes further injury because the vessels are then unable to supply tissues with blood. In fact, frostbite occurs more readily from touching cold metal objects because heat is rapidly transferred from the skin to metal. Frostbite can develop within 2-to-3 seconds when touching metal surfaces that are at or below 5 degrees Fahrenheit – therefore, touching surfaces at ambient temperatures below freezing with bare hands is not recommended. Liquids used in industry may also cause unexpected freezing injuries (incidents have occurred where pressurized liquid ammonia or petroleum has caused serious freezing injuries due to evaporative freezing).
Frostbite typically affects the extremities – particularly the face, ears, fingers & toes. Initial symptoms typically include skin that looks waxy & feels numb. Once damaged, tissues will always be more susceptible to frostbite in the future. The adverse effects of frostbite injuries may persist for several years after the initial injury. Cold, tingling, stinging – or an aching feeling – in the frostbitten area, is followed by numbness. The skin color turns red, then purple, then white or very pale & is cold to the touch; hard or blistering skin occurs in severe cases.
In cases of frostbite, call 911, do NOT rub the affected area – and especially do NOT rub areas affected by frostbite with ice or snow – this only causes further freezing! Wrap the area in a soft cloth; if help is delayed, immerse the affected area in warm (NOT hot) water. Don’t pour the warm water directly on the affected area because it will warm the tissue too fast. Warming should be gradual & take about 25-40 minutes. Do not warm the affected area of the skin if there is a chance of refreezing.
Chillblains are ulcers formed by damaged small blood vessels in the skin, caused by the repeated exposure of skin to temperatures just above freezing. Symptoms include redness, itching, inflammation & possible blistering; in severe cases ulceration may occur.In cases of chillblains, do NOT scratch the skin, but slowly warm the skin & keep any blisters or ulcers clean & covered. Corticosteroid creams can be used to relieve itching & swelling.
Understand the Impact of Alcohol, Caffeine and Smoking
In terms of preventing cold stress, planning for work in cold weather is the most important defense. Avoid alcohol, caffeine & smoking. Alcohol can impair judgement & cause expansion of blood vessels in the skin (a phenomena called cutaneous vasodilation) that impairs the body’s ability to regulate its temperature & reduce shivering. Caffeine increases urine production & blood flow at the surface of the skin (both lead to a loss of body heat & contribute to dehydration). Smoking decreases blood flow to the extremities & raises the risk of cold injury. Eat warm, high-calorie foods like hot pasta dishes.
Consider Exhaustion and Fatigue
Avoid exhaustion or fatigue because energy is needed to keep muscles warm. Do not sit or kneel on cold, unprotected surfaces. If possible, heavy work should be scheduled during the warmer parts of the day (e.g. mid-day through early afternoon), and breaks should be taken out of the cold. Also, try working in pairs in order to keep an eye on each other & watch for signs of cold stress – victims of hypothermia may not recognize symptoms.
Wear the Right Clothing
Protective Clothing tips: wearing the right clothing is the most important way to avoid cold stress. Cotton loses its insulation value when it becomes wet. Denim is loosely woven; it allows water to penetrate & allows cool winds to blow away body heat. Duck or goose down stops wind, but easily becomes waterlogged. Clear plastic or woven nylon is a good protection against wind & water, but provides little insulation & can prevent moisture from escaping. Wool on the other hand, retains its insulative qualities, even when wet. Wear at least three layers of clothing; wear a hat (wool knit caps or hat liners that extend down the back of the neck should be worn); wear insulted boots (tight-fitting footwear restricts blood flow, as can wearing too many socks); and wear insulated gloves (mittens are good for protection, but limit finger movement – it’s best to carry both mittens & gloves, and they should never be worn when wet) . A balaclava provides further face protection. If you get hot while working, open your jacket, but keep your hat & gloves on. Keep a change of dry clothing available in case work clothes become wet. Do not wear tight clothing which can restrict blood flow.
Engineering Controls are helpful in preventing cold injuries, and include using radiant heaters to warm workers, shielding work areas from drafts or winds, and using insulating material on equipment (especially when temperatures drop below 30 degrees Farenheit).
Although weather in Hampton Roads is usually mild, prepare for winter – even if it’s a short season. Ensure that your employees are aware of dangers in cold conditions.